Display device

ABSTRACT

A display device includes: a first substrate; a second substrate facing the first substrate; a light amount control layer between the first substrate and the second substrate; a first line disposed on the first substrate and extending in a first direction and a second line disposed on the first substrate and extending in a second direction which intersects the first direction; a light blocking member disposed on the first substrate and overlapping at least one of the first line and the second line; a plurality of color conversion layers on the second substrate in respective pixel areas; and a partition wall among the plurality of color conversion layers, corresponding to the first line and the second line. The partition wall has a width less than a width of the light blocking member.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of U.S. patentapplication Ser. No. 16/780,525 filed on Feb. 3, 2020, which is acontinuation application of U.S. patent application Ser. No. 15/459,452filed on Mar. 15, 2017 (now U.S. Pat. No. 10,551,672), which claimspriority under 35 USC § 119 Korean Patent Application No.10-2016-0031332, filed on Mar. 16, 2016, in the Korean IntellectualProperty Office (KIPO), the disclosures of which are incorporated hereinin their entirety by reference.

1. TECHNICAL FIELD

Exemplary embodiments relate to a display device, and more particularly,to a display device including a color conversion layer configured toimprove light efficiency.

2. DISCUSSION OF RELATED ART

Display devices are classified into a liquid crystal display (“LCD”)device, an organic light emitting diode (“OLED”) display device, aplasma display panel (“PDP”) device, an electrophoretic display (“EPD”)device, and the like, based on a light emitting scheme thereof.

Another example of the display devices is a photo-luminescent display(“PLD”) device, which includes a fluorescent pattern substituted for acolor filter pattern which is used in conventional display devices. Whenlight is transmitted through each color filter (e.g., one of a red colorfilter R, a green color filter G, and a blue color filter B) in theconventional display device, an amount of the light may decrease toabout ⅓ of an initial light due to the color filter. In order to addresssuch an issue, the PLD device may represent colors using a colorconversion layer including a fluorescent element in lieu of the colorfilter. Display devices that employ such a color conversion layerincluding a fluorescent element are advantageous in that viewing angleproperties may be improved and high color reproducibility may beachieved, but they require twice as much energy as that required by theconventional display devices to have a predetermined front luminance.

Accordingly, it is necessary that display devices that employ the colorconversion layer including fluorescent elements have a structure thatmay improve light extraction efficiency.

It is to be understood that this background of the technology section isintended to provide useful background for understanding the technologyand as such disclosed herein, the technology background section mayinclude ideas, concepts or recognitions that were not part of what wasknown or appreciated by those skilled in the pertinent art prior to acorresponding effective filing date of subject matter disclosed herein.

SUMMARY

Exemplary embodiments may be directed to a display device improved interms of light efficiency by modifying a configuration of a colorconversion layer without an additional process.

According to an exemplary embodiment, a display device includes: a firstsubstrate; a second substrate facing the first substrate; a light amountcontrol layer between the first substrate and the second substrate; afirst line disposed on the first substrate and extending in a firstdirection and a second line disposed on the first substrate andextending in a second direction which intersects the first direction; alight blocking member disposed on the first substrate and overlapping atleast one of the first line and the second line; a plurality of colorconversion layers on the second substrate in respective pixel areas; anda partition wall among the plurality of color conversion layers,corresponding to the first line and the second line. The partition wallhas a width less than a width of the light blocking member.

The display device may further include a polarizer between the secondsubstrate and the light amount control layer.

The color conversion layer may be on a lower surface of the secondsubstrate.

The display device may further include a dichroic reflection layerbetween the color conversion layer and the polarizer.

The display device may further include a polarizer above the secondsubstrate.

The color conversion layer may be above an upper surface of the secondsubstrate.

The color conversion layer may be between the second substrate and thepolarizer.

The polarizer may be between the second substrate and the colorconversion layer.

The display device may further include a third substrate above the colorconversion layer.

The color conversion layer may further include a low refractive indexlayer.

The low refractive index layer may be on surfaces of the colorconversion layer except a surface of the color conversion layer facingthe light amount control layer and disposed adjacent to the light amountcontrol layer.

A portion of the partition wall overlapping the second line may have awidth greater than a width of a portion of the partition walloverlapping the first line.

The first line may be a gate line, and the color conversion layer mayhave substantially a same color in an upper portion and a lower portionwith respect to the gate line.

The first line may be a data line, and the color conversion layer mayhave substantially a same color in a left portion and a right portionwith respect to the data line.

The color conversion layer may include a phosphor in an area defined bythe partition wall.

The phosphor may include at least one of a red phosphor, a greenphosphor, and a blue phosphor.

The color conversion layer may include a phosphor and a transparentlayer.

The display device may further include a thin film transistor at anintersecting area between the first line and the second line; and apixel electrode connected to the thin film transistor.

The light amount control layer may include liquid crystal molecules.

The light amount control layer may include a blue organic light emittinglayer.

The foregoing is illustrative only and is not intended to be in any waylimiting. In addition to the illustrative aspects, embodiments, andfeatures described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the inventive concept will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings, wherein:

FIG. 1 is an exploded perspective view illustrating a display deviceaccording to a first exemplary embodiment;

FIG. 2 is a schematic plan view illustrating a pixel of the displaydevice of FIG. 1;

FIG. 3 is a cross-sectional view taken along line II-IT of FIG. 2;

FIG. 4 is a plan view illustrating a color conversion layer of thedisplay device according to the first exemplary embodiment;

FIG. 5 is a cross-sectional view taken along line III-III′ of FIG. 2;

FIG. 6 is a cross-sectional view illustrating a display device accordingto a second exemplary embodiment;

FIG. 7 is a cross-sectional view illustrating a display device accordingto a third exemplary embodiment;

FIG. 8 is an exploded perspective view illustrating a display deviceaccording to a fourth exemplary embodiment;

FIG. 9 is a schematic cross-sectional view illustrating the displaydevice of FIG. 8;

FIG. 10 is a cross-sectional view illustrating a display deviceaccording to a fifth exemplary embodiment;

FIG. 11 is a cross-sectional view illustrating a display deviceaccording to a sixth exemplary embodiment; and

FIG. 12 is a cross-sectional view illustrating a display deviceaccording to a seventh exemplary embodiment.

DETAILED DESCRIPTION

Features of the inventive concept and methods for achieving them will bemade clear from exemplary embodiments described below in detail withreference to the accompanying drawings. The inventive concept may,however, be embodied in many different forms and should not be construedas being limited to the exemplary embodiments set forth herein. Rather,these exemplary embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventiveconcept to those skilled in the art. The inventive concept is merelydefined by the scope of the claims. Therefore, well-known constituentelements, operations and techniques are not described in detail in theexemplary embodiments in order to prevent the inventive concept frombeing obscurely interpreted. Like reference numerals refer to likeelements throughout the specification.

In the drawings, certain elements or shapes may be illustrated in anenlarged manner or in a simplified manner to better illustrate theinventive concept, and other elements present in an actual product mayalso be omitted. Thus, the drawings are intended to facilitate theunderstanding of the inventive concept.

When a layer, area, or plate is referred to as being “on” another layer,area, or plate, it may be directly on the other layer, area, or plate,or intervening layers, areas, or plates may be present therebetween.Conversely, when a layer, area, or plate is referred to as being“directly on” another layer, area, or plate, intervening layers, areas,or plates may be absent therebetween. Further when a layer, area, orplate is referred to as being “below” another layer, area, or plate, itmay be directly below the other layer, area, or plate, or interveninglayers, areas, or plates may be present therebetween. Conversely, when alayer, area, or plate is referred to as being “directly below” anotherlayer, area, or plate, intervening layers, areas, or plates may beabsent therebetween.

The spatially relative terms “below”, “beneath”, “less”, “above”,“upper”, and the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the drawings. For example, in the case wherea device shown in the drawing is turned over, the device positioned“below” or “beneath” another device may be placed “above” anotherdevice. Accordingly, the illustrative term “below” may include both thelower and upper positions. The device may also be oriented in the otherdirection, and thus the spatially relative terms may be interpreteddifferently depending on the orientations.

Throughout the specification, when an element is referred to as being“connected” to another element, the element is “directly connected” tothe other element, or “electrically connected” to the other element withone or more intervening elements interposed therebetween. It will befurther understood that the terms “comprises,” “comprising,” “includes”and/or “including,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that, although the terms “first,” “second,”“third,” and the like may be used herein to describe various elements,these elements should not be limited by these terms. These terms areonly used to distinguish one element from another element. Thus, “afirst element” discussed below could be termed “a second element” or “athird element,” and “a second element” and “a third element” can betermed likewise without departing from the teachings herein.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have a same meaning as commonly understood by thoseskilled in the art to which this disclosure pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the present specification.

Hereinafter, a display device according to a first exemplary embodimentwill be described in detail with reference to FIGS. 1, 2, 3, 4, and 5.

FIG. 1 is an exploded perspective view illustrating a display deviceaccording to a first exemplary embodiment, FIG. 2 is a schematic planview illustrating a pixel of the display device of FIG. 1, FIG. 3 is across-sectional view taken along line II-IT of FIG. 2, FIG. 4 is a planview illustrating a color conversion layer of the display deviceaccording to the first exemplary embodiment, and FIG. 5 is across-sectional view taken along line III-III′ of FIG. 2.

The display device includes: a first substrate; a first line on thefirst substrate and extending in a first direction; a second line on thefirst substrate and extending in a second direction which intersects thefirst direction; and a light blocking member on the first substrate andoverlapping at least one of the first line and the second line.

In descriptions pertaining to the display device according to the firstexemplary embodiment, a gate line GL, a data line DL, and a gate lightblocking member are to be described as the first line, the second line,and the light blocking member, respectively, by way of example.

Referring to FIGS. 1, 2, and 3, the display device includes: a firstsubstrate 110; a light amount control layer 130 on the first substrate110; a second substrate 120 on the light blocking layer 130 and opposingthe first substrate 110; a backlight unit 400 below the first substrate110; a first polarizer 10 below the first substrate 110; and a secondpolarizer 20 on the light amount control layer 130.

The second substrate 120 includes a plurality of color conversion layers200 in a plurality of pixel areas, respectively.

The first substrate 110 and the second substrate 120 may includetransparent materials such as glass or plastic.

The light amount control layer 130 and the plurality of color conversionlayers 200 are disposed between the first substrate 110 and the secondsubstrate 120. The color conversion layer 200 is disposed on the lightamount control layer 130.

The display device includes a plurality of pixels, and the plurality ofpixels may be arranged in a matrix form from a plane.

The backlight unit 400 is disposed below the first substrate 110. Thebacklight unit 400 includes a light source 410 and a light guide plate420. The backlight unit 400 may irradiate ultraviolet light, rearultraviolet light, or blue light.

A dichroic reflection layer 240 is disposed below the color conversionlayer 200. The dichroic reflection layer 240 may include a dichroicfilter.

The dichroic filter may serve to reflect a second light having adifferent wavelength from a wavelength of a first light incidentthereto, and to transmit in a selective manner a light havingsubstantially a same wavelength as that of the first light. The firstlight corresponds to a blue light emitted from the light source 410, andthe second light having a different wavelength from that of the firstlight corresponds to a red light or a green light converted in terms ofwavelength by the color conversion layer 200.

Among the second light emitted from the color conversion layer 200, alight emitted toward a rear portion of a display panel is reflected bythe dichroic reflection layer 240 to be emitted toward the front of thedisplay panel.

The dichroic reflection layer 240 has a multilayer structure in whichhigh refractive index thin films and low refractive index thin films arealternately stacked. The dichroic reflection layer 240 may serve aselective light transmitting function based on its high reflectancewhich may be obtained by a multilayer interference phenomenon. The lowrefractive index thin film may include MgF₂ and SiO₂, for example, andthe high refractive index thin film may include Ag, TiO₂, Ti₂O₃, andTa₂O₃, for example, but exemplary embodiments are not limited thereto. Athickness of each of the thin films may be determined in a range ofabout ⅛ to about ½ of a wavelength of transmitted light.

In a case where the dichroic reflection layer 240 has a multilayerstructure in which a plurality of dielectric thin films, each havingdifferent refractive indices, are stacked, the multilayer interferencephenomenon may arise in the dichroic reflection layer 240 due to amirror surface which has significantly higher reflectance than that ofmetal. Such a dichroic reflection layer 240 may also be referred to asan edge filter in an optical field, and may be designed to have areflectance that radically changes with respect to a predeterminedwavelength.

The dichroic reflection layer 240 may improve light efficiency bytransmitting and/or reflecting a light of a predetermined wavelength ina selective manner based on a configuration of the dielectric thin film.For example, in a case where the first light incident to the colorconversion layer 200 is blue light, the dichroic reflection layer 240may be designed to transmit the blue light, and reflect green light andred light. Accordingly, among green light and red light emitted from thecolor conversion layer 200, the second light emitted toward the rearportion of the display panel is reflected by the dichroic reflectionlayer 240 to be emitted toward the front of the display panel.Accordingly, the dichroic reflection layer 240 may enhance lightefficiency of the color conversion layer 200.

When a surface of the first substrate 110 and a surface of the secondsubstrate 120 that face each other are defined as inner surfaces of thecorresponding substrates 110, 120, respectively, and surfaces oppositeto the inner surfaces are defined as outer surfaces of the correspondingsubstrates 110, 120, respectively, the first polarizer 10 is disposed onthe outer surface of the first substrate 110 and the second polarizer 20is disposed on the inner surface of the second substrate 120. Atransmission axis of the first polarizer 10 may be substantiallyorthogonal to a transmission axis of the second polarizer 20.

The light amount control layer 130 may include a plurality of liquidcrystal molecules 131. The light amount control layer 130 may include alight blocking member 132 which defines a boundary among the pluralityof pixels.

The plurality of color conversion layers 200 include a partition wall220 which define a plurality of pixel areas from one another and aplurality of fluorescent elements (hereinafter, “phosphor”) 210R, 210G,and 210B disposed in the plurality of pixel areas, respectively, definedby the partition wall 220.

The plurality of color conversion layers 200 may include a first colorpixel, a second color pixel, and a third color pixel, for example. Forexample, the first color pixel may be a red pixel, the second colorpixel may be a green pixel, and the third color pixel may be a bluepixel. The red pixel includes a red phosphor 210R, the green pixelincludes a green phosphor 210G, and the blue pixel includes a bluephosphor 210B.

A light transmitted through the red pixel of the color conversion layer200 represents a red color, a light transmitted through the green pixelthereof represents a green color, and a light transmitted through theblue pixel thereof represents a blue color.

The color conversion layer 200 may include a resin 210 including thephosphors 210R, 210G, and 210B. The phosphor is a material that emits,upon being irradiated with light, radiant light, or the like,fluorescent light having an intrinsic color of the correspondingphosphor regardless of the color of the light irradiated thereto. Inaddition, the light is emitted toward all directions regardless of thepropagation direction of the light irradiated thereto.

In an exemplary embodiment, although not illustrated, the colorconversion layer 200 may include a phosphor having a different colorother than the above-described colors, and the phosphor may scatterlight of a fourth color.

The phosphors 210R, 210G, and 210B of the color conversion layer 200 mayinclude quantum dot particles. A quantum dot particle is a wavelengthconverting particle that converts a wavelength of a light to emit adesired light. A range of wavelength a quantum dot particle may convertvaries based on the size of the quantum dot particle. Accordingly, alight of a desired color may be obtained by adjusting a diameter of thequantum dot particle.

The quantum dot particle has a high quantum yield and a high extinctioncoefficient which is about a hundred times to about a thousand timesgreater than an extinction coefficient of a general fluorescent element,and thus may emit significantly intense fluorescent light. Inparticular, the quantum dot particle may receive a light of a shortwavelength and shift the short wavelength to emit a light of a longerwavelength.

The quantum dot particle may have a structure including a corenanocrystal and a shell nanocrystal surrounding the core nanocrystal. Inan exemplary embodiment, the quantum dot particle may further include anorganic ligand bonded to the shell nanocrystal. In an exemplaryembodiment, the quantum dot particle may further include an organiccoating layer surrounding the shell nanocrystal.

The shell nanocrystal may have two or more layers. The shell nanocrystalis formed on a surface of the core nanocrystal. Using the shellnanocrystal forming a shell layer, the quantum dot particle may lengthena wavelength of a light incident to the core nanocyrstal, thus enhancinglight efficiency.

The quantum dot particle may include at least one substance of group IIcompound semiconductors, group III compound semiconductors, group Vcompound semiconductors, and group VI compound semiconductors. Forexample, the core nanocrystal may include at least one of: PbSe, InAs,PbS, CdSe, InGaP, CdTe, CdS, ZnSe, ZnTe, ZnS, HgTe or HgS. Further, theshell nanocrystal may include at least one of: CuZnS, CdSe, CdTe, CdS,ZnSe, ZnTe, ZnS, HgTe or HgS.

For example, in a case where the core nanocrystal includes CdSe, a bluelight may be emitted when a diameter of the quantum dot particle is in arange of about 1 nm to about 3 nm, a green light may be emitted when thediameter of the quantum dot is in a range of about 3 nm to about 5 nm,and a red light may be emitted when the diameter of the quantum dot isin a range of about 7 nm to about 10 nm.

A wavelength of light emitted from the quantum dot particle may beadjusted based on the size of the quantum dot particle or a molar ratiobetween a nanocrystal precursor and a molecular cluster compound in afabrication process. An organic ligand serves to stabilize the quantumdot particle that is unstable after fabricated. Examples of the organicligand may include pyridine, mercapto alcohol, thiol, phosphine, andphosphine oxide, for example. When fabricated, a quantum dot particlemay have a dangling bond on an outer side thereof, and thus may becomeunstable. In such an example, however, an end of the organic ligand isin a non-bonding state, and the non-bonding end of the organic ligandmay bond to the dangling bond such that the quantum dot particle may bestabilized.

The quantum dot particle may be fabricated in a wet-chemical methodwhereby a precursor material is put into an organic solvent such thatthe particle may grow. In an exemplary embodiment, the quantum dotparticle may be fabricated through the wet-chemical method.

In an exemplary embodiment, the partition wall 220 of the colorconversion layer 200 may have a lattice form corresponding to the gateline GL and the data line DL on the first substrate 110.

Hereinafter, the partition wall 220 of the color conversion layer 200 inthe display device according to the first exemplary embodiment will bedescribed with reference to FIGS. 2 and 4.

First, referring to FIG. 2, the display device according to the firstexemplary embodiment includes the gate line GL extending in a horizontaldirection, the data line DL extending in a vertical direction whichintersects the horizontal direction, a thin film transistor (“TFT”) atintersecting areas between the gate line GL and the data line DL, and afirst electrode 191 connected to the TFT.

As illustrated in FIG. 2, the red pixel R, the green pixel G, and theblue pixel B are arranged in a line to form a pixel. Pixels ofsubstantially a same color are disposed in an upper portion and a lowerportion with respect to the gate line GL, and pixels of different colorsare disposed in a left portion and a right portion with respect to thedata line DL, respectively. For example, the red pixels R may bedisposed in the upper portion and the lower portion, and the blue pixelB may be disposed on the left side of the red pixel R, and the greenpixel G may be disposed on the right side of the red pixel R.

As described above, the plurality of color conversion layers 200 includethe partition wall 220 which defines the plurality of pixel areas fromone another. The partition wall 220 of the color conversion layer 200 isdisposed corresponding to an edge area of the pixel area to block light.The partition wall 220 is disposed to overlap at least one of the gateline GL and the data line DL.

For example, the partition wall 220 may overlap a light blocking memberthat overlaps at least one of the gate line GL and the data line DL. Inan exemplary embodiment, an example of the partition wall 220overlapping the gate light blocking member will be described by way ofexample.

In typical display devices, the gate light blocking member serves tocontrol light leakage and photo leakage. In an exemplary embodiment ofthe display device, as the gate light blocking member controls lightleakage in a lower display panel, it is unnecessary that the partitionwall 220 of the color conversion layer 200 has substantially a samewidth as a width of the gate light blocking member.

The partition wall 220 of the color conversion layer 200 may have awidth less and a breadth less than those of the gate light blockingmember. However, exemplary embodiments are not limited thereto, and thepartition wall 220 of the color conversion layer 200 may be omitted.

Referring to FIG. 4, the plurality of color conversion layers 200include the partition wall 220 defining the plurality of pixel areas andthe plurality of phosphors 210R, 210G, and 210B in the plurality ofpixel areas defined by the partition wall 220.

As described hereinabove, the partition wall 220 may have a lattice formcorresponding to the gate line GL and the data line DL. In addition, aportion of the partition wall 220 overlapping the data line DL may havea width greater than a width of a portion of the partition wall 220overlapping the gate line GL.

As illustrated in FIG. 4, a portion of the partition wall 220 extendingin a horizontal direction (hereinafter, a horizontal portion) and aportion of the partition wall 220 extending in a vertical direction(hereinafter, a vertical portion) intersect one another to form alattice form.

In an exemplary embodiment, the horizontal portion of the partition wall220 may correspond to the gate light blocking member and the verticalportion thereof may correspond to a data light blocking member.Accordingly, a width W2 of the vertical portion of the partition wall220 may be greater than a width W1 of the horizontal portion of thepartition wall 220 (W1<W2).

The width W1 of the horizontal portion of the partition wall 220 may bereduced, because pixels of substantially a same color are disposed in anupper portion and a lower portion with respect to the horizontal portionof the partition wall 220, thus not significantly affecting colors.However, because pixels of different colors are disposed in a leftportion and a right portion with respect to the vertical portion of thepartition wall 220 to affect colors, it is desirable that the width W2of the vertical portion is substantially the same as a width of lightblocking member.

According to the first exemplary embodiment, the gate line GL and thedata line DL are described as the first line and the second line,respectively, by way of example. However, exemplary embodiments are notlimited thereto, and the first line and the second line may be the dataline DL and the gate line GL, respectively.

As described hereinabove, in an exemplary embodiment of the displaydevice, as the partition wall 220 of the color conversion layer 200 isreduced, a light emission area may be expanded and light extractionefficiency may be improved.

Hereinbelow, a pixel of a display device will be described in detailwith reference to FIG. 5.

The display device includes a lower display panel 30 and an upperdisplay panel 40 opposing each other, and the light amount control layer130 between the two display panels 30 and 40. In FIG. 5, the lightamount control layer 130 will be described with respect to a liquidcrystal layer, by way of example.

First, the lower display panel 30 will be described.

The gate line GL and a storage electrode line 112 are disposed along onedirection on the first substrate 110. The first substrate 110 mayinclude transparent materials such as glass or plastic.

The gate line GL largely extends in a horizontal direction and transmitsa gate signal. A gate electrode 111 protrudes from the gate line GL.

The storage electrode line 112 extends in substantially a same directionas a direction in which the gate line GL extends, and a predeterminedvoltage is applied to the storage electrode line 112. A storageelectrode 113 protrudes from the storage electrode line 112.

A gate insulating layer 140 is formed on the gate line GL, the storageelectrode line 112, the gate electrode 111, and the storage electrode113. The gate insulating layer 140 may include an inorganic insulatingmaterial such as silicon nitride (SiN_(x)) and silicon oxide (SiO₂). Inaddition, the gate insulating layer 140 may have a monolayer structureor a multilayer structure.

A semiconductor layer 150 is formed on the gate insulating layer 140.The semiconductor layer 150 may be disposed on the gate electrode 111.The semiconductor layer 150 may include amorphous silicon,polycrystalline silicon, and/or metal oxide.

An ohmic contact member (not illustrated) may further be formed on thesemiconductor layer 150. The data line DL, a source electrode 170, and adrain electrode 171 are formed on the semiconductor layer 150 and thegate insulating layer 140. The semiconductor layer 150 may also beformed below the data line DL, as well as on the gate electrode 111.

The data line DL transmits a data voltage and largely extends in avertical direction to intersect the gate line GL.

The source electrode 170 protrudes from the data line DL. The sourceelectrode 170 may be curved into a C-like shape above the gate electrode111.

The drain electrode 171 is disposed above the gate electrode 111 to bespaced apart from the source electrode 170. A channel is formed in anexposed portion of the semiconductor layer 150 between the sourceelectrode 170 and the drain electrode 171 that are spaced apart fromeach other.

The gate electrode 111, the semiconductor layer 150, the sourceelectrode 170, and the drain electrode 171, described hereinabove,define a switching element.

A first protection layer 180 p is formed on the data line DL, the sourceelectrode 170, the drain electrode 171, and an exposed portion of thesemiconductor layer 150 between the source electrode 170 and the drainelectrode 171. The first protection layer 180 p may include an inorganicinsulating material such as silicon nitride (SiN_(x)) and silicon oxide(SiO₂).

A planarization layer 160 is disposed on the first protection layer 180p. The planarization layer 160 may include at least one selected fromthe group consisting of: a polyacrylate resin, an epoxy resin, aphenolic resin, a polyamide resin, a polyimide resin, an unsaturatedpolyester resin, a poly-phenylenether resin, a poly-phenylenesulfideresin, and benzocyclobutene (BCB).

A second protection layer 180 q is further formed on the planarizationlayer 160. The second protection layer 180 q may include an inorganicinsulating material such as silicon nitride (SiN_(x)) and silicon oxide(SiO₂). The second protection layer 180 q may effectively reduceloosening off of the planarization layer 160 and contamination of thelight amount control layer 130 from an organic material permeating fromthe planarization layer 160, thus effectively reducing defects such asimage sticking that may occur when a screen is operated.

A contact hole 182 extending to and exposing the drain electrode 171 isdefined in the first protection layer 180 p, the planarization layer160, and the second protection layer 180 q.

The first electrode 191 is formed on the first protection layer 180 q.The first electrode 191 is connected to the drain electrode 171 throughthe contact hole 182. The first electrode 191 receives a data voltagefrom the drain electrode 171.

The first electrode 191, applied with the data voltage, along with asecond electrode 270 of the upper display panel 40 to be describedhereinbelow, generates an electric field which may determine anorientation of the liquid crystal molecules 131 of the light amountcontrol layer 130 between the first and second electrodes 191 and 270.Based on the orientation of the liquid crystal molecules 131, luminanceof light transmitted through the light amount control layer 130 mayvary.

The first electrode 191 and the second electrode 270, along with thelight amount control layer 130 therebetween, form a liquid crystalcapacitor to maintain the applied voltage even after the TFT is turnedoff.

The first electrode 191 may overlap the storage electrode line 112 aswell as the storage electrode 113, thus forming a storage capacitor. Thestorage capacitor may enhance voltage maintaining capability of theliquid crystal capacitor.

A first alignment layer 11 is formed on the first electrode 191. Thefirst alignment layer 11 may be a vertically-aligned alignment layer oran alignment layer that is photo-aligned using a photo-polymerizablematerial.

Hereinafter, the upper display panel 40 will be described.

The second electrode 270 is disposed on the second substrate 120. Thesecond electrode 270 may include a transparent metal material such asITO and IZO. A predetermined voltage may be applied to the secondelectrode 270, and an electric field may be generated between the firstelectrode 191 and the second electrode 270.

A second alignment layer 21 is formed on the second electrode 270. Thesecond alignment layer 21 may be a vertically-aligned alignment layer oran alignment layer that is photo-aligned using a photopolymerizablematerial.

Hereinafter, second and third exemplary embodiments will be describedwith reference to FIGS. 6 and 7.

FIG. 6 is a cross-sectional view illustrating a display device accordingto a second exemplary embodiment, and FIG. 7 is a cross-sectional viewillustrating a display device according to a third exemplary embodiment.

Referring to FIG. 6, a color conversion layer 200 further includes a lowrefractive index layer 250. For example, the low refractive index layer250 is provided on at least one side of the color conversion layer 200to cover at least a portion of the color conversion layer 200.

The low refractive index layer 250 reflects a first light toward thecolor conversion layer 200, in order to increase frequency of use of thefirst light in the color conversion layer 200. On the contrary, the lowrefractive index layer 250 transmits a light in a visible ray range tobe directly perceived by an eye of a user. According to the secondexemplary embodiment, as illustrated in FIG. 6, the low refractive indexlayer 250 may cover surfaces of the color conversion layer 200, except asurface thereof facing a light amount control layer 130. That is, thelow refractive index layer 250 may cover a surface opposite to thesurface of the color conversion layer 200 facing the light amountcontrol layer 130 and the entirety of surfaces contacting a partitionwall 220. For example, the low refractive index layer 250 is disposedbetween the second substrate and the resins including the phosphors210R, 210G, 210B, the partition wall 220 and the resins including thephosphors 210R, 210G, 210B. The low refractive index layer 250 mayinclude a dielectric thin film. That is, the low refractive index layer250 includes a thin film having a low refractive index, thus forming ahalf mirror that reflects light of a predetermined wavelength. The thinfilm may include various inorganic materials, e.g., silicon oxide,titanium oxide, and silicon nitride.

Configurations of the second exemplary embodiment are substantially thesame as configurations of the first exemplary embodiment, except thatthe low refractive index layer 250 is provided between the colorconversion layer 200 and a second substrate 120. As the color conversionlayer 200 further includes the low refractive index layer 250, lightefficiency may be improved.

Referring to FIG. 7, the color conversion layer 200 and a dichroicreflection layer 240 may be disposed on an upper surface of the secondsubstrate 120. The color conversion layer 200 and the dichroicreflection layer 240 may be disposed between the second substrate 120and a second polarizer 20.

In a display device according to a third exemplary embodiment, a colorconversion layer 200 and a dichroic reflection layer 240 are disposed ina different manner from the disposition of the color conversion layer200 and the dichroic reflection layer 240 in the display deviceaccording to the first exemplary embodiment. Although the positions ofthe color conversion layer 200 and the dichroic reflection layer 240 arechanged, a light extraction area is expanded as in the first exemplaryembodiment.

Hereinafter, a display device according to a fourth exemplary embodimentwill be described with reference to FIGS. 8 and 9. According to thefourth exemplary embodiment, a color conversion layer 200 may bedisposed above a second substrate 120, and a second polarizer 20 may bedisposed between the color conversion layer 200 and the second substrate120.

FIG. 8 is an exploded perspective view illustrating the display deviceaccording to the fourth exemplary embodiment, and FIG. 9 is a schematiccross-sectional view illustrating the display device of FIG. 8.

Referring to FIGS. 8 and 9, the display device further includes a thirdsubstrate 300.

The third substrate 300 may include transparent materials such as glassor plastic. The third substrate 300 may be a protective glass. The colorconversion layer 200 and a dichroic reflection layer 240 are disposedbetween the second substrate 120 and the third substrate 300. The colorconversion layer 200 and the dichroic reflection layer 240 are formed onthe third substrate 300 in a separate manner and then may be attached onthe second substrate 120.

Hereinafter, a display device according to a fifth exemplary embodimentwill be described with reference to FIG. 10.

FIG. 10 is a cross-sectional view illustrating the display deviceaccording to the fifth exemplary embodiment.

Referring to FIG. 10, a transparent layer 230 of a color conversionlayer 200 is a transparent transmissive layer not having any color. Thetransparent layer 230 may include a colorless transparent resin or maybe void, not including any material.

The transparent layer 230 corresponds to a blue pixel of the colorconversion layer 200 and blue light propagating through a firstsubstrate 110 and a light amount control layer 130 may be intactlytransmitted therethrough, such that luminance of the blue light mayincrease. In addition, in a case where the transparent layer 230 is void(i.e., does not include any material), a separate process formanufacturing a blue pixel is unnecessary such that a manufacturingprocess may be simplified and manufacturing costs may be reduced.

Hereinafter, a display device according to a sixth exemplary embodimentwill be described with reference to FIG. 11. Configurations of thedisplay device according to the sixth exemplary embodiment aresubstantially the same as those of the display device according to thefirst exemplary embodiment, except that a first polarizer 10 is anin-cell polarizer that is disposed in a display panel. Descriptionspertaining to the same configurations described hereinabove will beomitted, for ease of description.

FIG. 11 is a cross-sectional view illustrating the display deviceaccording to the sixth exemplary embodiment.

Referring to FIG. 11, in the display device according to the sixthexemplary embodiment, the first polarizer 10 is disposed above a firstsubstrate 110.

The first polarizer 10 has a structure in which a wire grid pattern isformed on a red pixel, a green pixel, and a blue pixel in a unit pixel.The wire grid pattern is a stripe pattern having a line width less and agap less than wavelengths of a red light, a green light, and a bluelight within a wavelength range of visible light that humans canperceive. When light is incident to the wire grid pattern, a polarizedlight parallel to the wire grid pattern is reflected and a polarizedlight perpendicular to the wire grid pattern is transmittedtherethrough.

The wire grid pattern may be formed in the following manner: in a statethat an imprinting resin, including a conductive material, is formed ona substrate, imprinting is repeatedly performed on the imprinting resinusing a stamp formed with a wire grid pattern. In an alternativeexemplary embodiment, the wire grid pattern may be formed through alithography process, based on laser interference, using a mask having apattern corresponding to the wire grid pattern.

As illustrated in FIG. 11, the wire grid pattern of the first polarizer10 is depicted as having substantially a same width and substantially asame gap in each pixel, but the width and the gap of the wire gridpattern may vary corresponding to respective colors of the pixels.

The wire grid pattern may be designed to have suitable values for thepitch, the width, and the height, corresponding to the wavelength ofrespective colors of the unit pixels, to form a suitable pattern shape.

The second polarizer 20 may use a polarizer typically used in thepertinent art which includes, for example, a polyvinyl alcohol (“PVA”)film, which is formed by absorbing and elongating iodine, and a filmprotecting the PVA film.

An optical transmission axis of the first polarizer 10 and an opticaltransmission axis of the second polarizer 20 may be orthogonal to eachother.

As including the first polarizer 10 having a wire grid pattern that maytransmit or reflect polarized light in a selective manner, the displaydevice according to the sixth exemplary embodiment may have highpolarization efficiency, high transmittance, and a wide viewing angle.

Hereinafter, a display device according to a seventh exemplaryembodiment will be described with reference to FIG. 12. The displaydevice according to the seventh exemplary embodiment is an organic lightemitting diode (“OLED”) display device including the color conversionlayer 200 of the fourth exemplary embodiment.

FIG. 12 is a cross-sectional view to describe a configuration of an OLEDaccording to the seventh exemplary embodiment, which will be describedhereinbelow.

Referring to FIG. 12, a first substrate 500 having a red pixel area R, agreen pixel area G, and a blue pixel area B may include an insulatingmaterial selected from the group consisting of glass, quartz, ceramic,plastic, or the like. However, the seventh exemplary embodiment is notlimited thereto, and the first substrate 500 may include a metalmaterial such as stainless steel.

A buffer layer 510 is disposed over an entire surface of the firstsubstrate 500. The buffer layer 510 is configured to protect a TFT, tobe formed in a subsequent process, from undesirable materials that leaksfrom the first substrate 500.

Semiconductor layers 520 having source areas 520 a, drain areas 520 b,and channel areas 520 c corresponding to each of the pixel areas R, G,and B are disposed on the buffer layer 510.

A gate insulating layer 530 is disposed on the semiconductor layers 520,and gate electrodes 540 are disposed on the gate insulating layer 530corresponding to each of the channel areas 520 c.

Subsequently, an insulating interlayer 550 is disposed to cover the gateelectrodes 540, and source electrodes 560 a and drain electrodes 560 belectrically contacting the source areas 520 a and the drain areas 520b, respectively, are disposed on the insulating interlayer 550.

The semiconductor layers 520, the source electrodes 560 a, the drainelectrodes 560 b, and the gate electrodes 540 define TFTs on the pixelareas R, G, and B, respectively.

Subsequently, a planarization layer 570 is disposed thereon to cover theTFTs, and via holes are defined in the planarization layer 570 to exposethe drain electrodes 560 a, respectively.

The first electrodes 580, spaced apart from one another corresponding toeach of the pixel areas R, G, and B, are disposed on the substrate inwhich the via holes are defined. Accordingly, the first electrodes 580are electrically connected to the drain electrodes 560 a, i.e., theTFTs, respectively, through the via holes. In an exemplary embodiment,the first electrodes 580 may have a structure in which a reflectivemetal layer, i.e., a reflective electrode including, e.g., silver,aluminum, a silver alloy, and an aluminum alloy which have highreflectance, and a transparent conductive layer, disposed on thereflective metal layer and having a high work function, are stacked. Thefirst electrode 580 which is the reflective electrode may be an anode ora cathode.

A pixel defining layer 590, having an aperture exposing a portion of asurface of the first electrodes 580, is disposed on the substrate onwhich the first electrodes 580 are disposed. The pixel defining layer590 may be an acrylic organic layer, for example.

Subsequently, an organic layer 600, including at least a blue lightemitting layer is formed in each of the apertures.

The light emitting layer may include only hosts or only dopants, butsuch a light emitting layer is disadvantageous in that it hassignificantly low efficiency and luminance and exhibits characteristicsof an excimer, in addition to the intrinsic characteristics of eachmolecule, due to a self-packing phenomenon that occurs among respectiveones of the molecules. Accordingly, it is desirable that the lightemitting layer is formed through doping dopants with hosts.

The blue light emitting layer may use an antracene-based material as ahost material. Examples of the antracene-based material may includebinaphtyl-methylantracene (MADN) and binaphthyl-t-butylantracene (TBDN).

The dopant material of the blue light emitting layer may use a lightemitting material having a peak wavelength ranging from about 450 nm toabout 475 nm in a light spectrum and having a main-peak area of about80% or more, so as to enhance color purity and light emissionefficiency.

The blue dopant may use a material having two or more aromatic amineunits selected from the group consisting of: a perylene-based material,an anthanthrene-based material, a stilbene-based material, and anon-stilbene-based material. For example, the blue dopant may use anon-stilbene-based dopant.

The organic layer 600 may further include at least one of a holeinjection layer, a hole transport layer, an electron transport layer,and an electron injection layer, in addition to the light emittinglayer.

A second electrode 610 is disposed on the organic layer 600. In thepresent exemplary embodiment, the second electrode 610 is a transparentelectrode, and light emitted from the organic light emitting layer istransmitted through the second electrode 610 to be emitted outwards. Thesecond electrode 610 may be a cathode when the first electrodes 580 arean anode, and may be an anode when the first electrodes 580 are acathode.

The second electrode 610 may include a transparent electrode including,for example, ITO or IZO, or may include a transmissive electrode, havinga small thickness to transmit light, which includes a material selectedfrom the group consisting of: Mg, Ag, Al, Ca, and alloys thereof thathave low work functions. Accordingly, an OLED including the blue lightemitting layer may be provided, having high color purity, highefficiency, and long life span.

A protective layer 700 is disposed on the second electrode 610. Theprotective layer 700 may protect interior components, such as the OLEDfrom impact that may be externally imposed to the OLED display device.

Further, the OLED display device according to the seventh exemplaryembodiment includes a blue OLED having high color purity and long lifespan and a color conversion layer having an expanded light emission areasuch that light efficiency may be improved.

As described hereinabove, an exemplary embodiment of the display deviceis susceptible to various modifications, for example, disposing adichroic reflection layer on a lower surface of the color conversionlayer, disposing a low refractive index layer in the color conversionlayer, and reducing a partition wall of the color conversion layer.Improvement in light extraction efficiency is measured for eachexemplary embodiment, the results of which are described hereinbelow inTable 1.

TABLE 1 Light amount (measured) Dichroic reflection layer Not appliedApplied Width of partition wall (μm) 72 72 49 26 0 Low refractive Notapplied 100% 115% 125% 142% 160% index layer Applied 120% 132% 143% 162%177%

Referring to Table 1, it is verified that a display device including thedichroic reflection layer on the lower surface of the color conversionlayer is increased by about 15% in terms of a light amount, a displaydevice including the low refractive index layer in the color conversionlayer by about 20% in terms of a light amount, and a display deviceincluding both of the dichroic reflection layer and the low refractiveindex layer by about 32% in terms of a light amount.

In an exemplary embodiment, when the dichroic reflection layer isprovided on the lower surface of the color conversion layer, displaydevices including partition walls, among the color conversion layers, ofwhich widths are reduced from about 72 μm to about 49 μm, about 26 μm,and about 0 μm are increased by about 10%, about 27%, and about 45%,respectively, in terms of a light amount.

When both of the dichroic reflection layer and the low refractive indexlayer are provided, display devices including partition walls, among thecolor conversion layers, of which widths are reduced from about 72 μm toabout 49 μm, about 26 μm, and about 0 μm are increased by about 11%,about 30%, and about 45%, respectively, in terms of a light amount.

As such, an exemplary embodiment of a display device may be improved interms of light extraction efficiency by reducing the partition wall ofthe color conversion layer to expand light emission area.

As set forth above, in a display device according to one or moreexemplary embodiments, the light emission area may be expanded byadjusting the width of the partition wall among the color conversionlayers such that light efficiency may be improved.

While the inventive concept has been shown and described with referenceto the exemplary embodiments thereof, it will be apparent to those ofordinary skill in the art that various changes in form and detail may bemade thereto without departing from the spirit and scope of theinventive concept.

What is claimed is:
 1. A display device comprising: a first substrate; asecond substrate facing the first substrate; a light blocking memberdisposed between the first substrate and the second substrate; aplurality of color conversion layers between the first substrate and thesecond substrate in respective pixel areas; a partition wall among theplurality of color conversion layers; and a blue light providing unitbelow the color conversion layers.
 2. The display device as claimed inclaim 1, wherein the partition wall has a width less than a width of thelight blocking member.
 3. The display device as claimed in claim 1,further comprising a first line disposed on the first substrate andextending in a first direction and a second line disposed on the firstsubstrate and extending in a second direction which intersects the firstdirection, and wherein the partition wall is corresponding to the firstline and the second line.
 4. The display device as claimed in claim 3,wherein the first line is a gate line, and the second line is a dataline.
 5. The display device as claimed in claim 1, wherein the colorconversion layer is on a lower surface of the second substrate.
 6. Thedisplay device as claimed in claim 1, further comprising a dichroicblocking layer on the color conversion layer.
 7. The display device asclaimed in claim 1, wherein the color conversion layer further comprisesa low refractive index layer.
 8. The display device as claimed in claim1, wherein a portion of the partition wall corresponding to the secondline has a width greater than a width of a portion of the partition wallcorresponding to the first line.
 9. The display device as claimed inclaim 1, wherein the color conversion layer comprises a phosphor in anarea defined by the partition wall.
 10. The display device as claimed inclaim 9, wherein the phosphor comprises a red phosphor and a greenphosphor.
 11. The display device as claimed in claim 1, wherein thecolor conversion layer comprises a phosphor and a transparent layer. 12.The display device as claimed in claim 1, further comprising a thin filmtransistor at an intersecting area between the first line and the secondline; and a pixel electrode connected to the thin film transistor.